Most Fediverse software supports image uploads, so there’s no reason to use Imgur for image hosting. Hell, even on my small single-user server (atomicpoet.org), image hosting is easy peasy. Not only is Imgur not needed, they’re an annoyance for those of us who are used to seeing images natively on the Fediverse.
I know habits are hard to break, but just remember: this isn’t Reddit 🙂
Note that not all instances do this. Especially not necessarily if they aren’t mastodon. My calckey instance for example has it optional and i have it off there. Akkoma i know also can do it optionally.